The most accurate php truncation string length function, intercepting string _ PHP Tutorial

The most accurate php intercepts the string length function and intercepts the string. The most accurate php truncation string length function, the interception string is the most precise interception length, in fact, I am not sure whether it is the most accurate, for more details, see the following results to find the most accurate php string truncation function and string truncation function.

In fact, I am not sure whether it is the most precise part of the length. For more details, see the following results:
First test the string:

<? Php header ("Content-Type: text/html; charset = utf-8"); echo cn_substr_utf8 ('I Am A, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 ('AI \' 2145m a ch3 I [is a, a, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' [I, it's a, it's a, and ha, oh, it's also, country! ', 12); echo'
', Cn_substr_utf8 (' I Am A, A, and a, Oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' I am, one, one, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' I, yes, one, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' I'm asd 1, A, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' [I \'m [is a, A, and a, Oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' [I \'m a ch I [is a, a, and ha, oh, also, country! ', 12); echo'
', Cn_substr_utf8 (' [I \ '2145m a ch3 I [is a, a, and a, Oh, also, country! ', 12 );

The following describes how to precisely intercept a string:

The specific function code is as follows:

// UTF-8 Chinese truncation, single-byte truncation mode function cn_substr_utf8 ($ str, $ length, $ append = '... ', $ start = 0) {if (strlen ($ str) <$ start + 1) {return '';} preg_match_all ("/. /su ", $ str, $ ar); $ str2 =''; $ tstr = ''; // www.phpernote.com for ($ I = 0; isset ($ ar [0] [$ I]); $ I ++) {if (strlen ($ tstr) <$ start) {$ tstr. = $ ar [0] [$ I];} else {if (strlen ($ str2) <$ length + strlen ($ ar [0] [$ I]) {$ str2. = $ ar [0] [$ I];} else {break ;}} return $ str ==$ str2? $ Str2: $ str2. $ append ;}

If you think it is not accurate enough, you can make improvements or innovations on this basis. I hope this article on php's string length function truncation will be helpful for your learning.

In fact, I am not sure whether it is the most precise part of the length. For more details, see the following results...